The refueling of commercial airplanes is accomplished through pressurized fuel systems. The tank inlet on the airplane is usually located under the wing, and a nozzle mounted on the end of a supply hose is attached to the tank inlet and includes a valve which displaces the tank inlet valve as the nozzle valve is opened to permit the flow of fuel through the nozzle and through the tank inlet. Such aircraft refueling nozzles must include safety devices to prevent fuel spillage, and be as foolproof and trouble-free as possible.
Present aircraft fueling nozzles utilizing retractable and extendable valves locate valve actuating structure within the valve flow passage causing a restriction with respect to fuel flow, and the location of actuating and control parts within the fuel passage presents the possibility of loose nozzle parts entering the fuel system and flowing into the aircraft fuel tank.
It is an object of the invention to provide a improved fuel nozzle for pressurized fuel systems such as utilized with aircraft wherein fuel flow through the nozzle is substantially unrestricted and valve actuating apparatus is removed from the flow passage.
Another object of the invention is to provide a pressurized fuel nozzle having an extendable and retractable valve wherein the operation of the valve is positive and trouble-free and wherein the operator may readily discern the valve position during all conditions of operation.
A further object of the invention is to provide a fuel nozzle for a pressurized fuel system having a retractable and extendable valve wherein the valve operator is rendered inoperative until the nozzle is fully connected and locked to the tank inlet.
Yet another object of the invention is to provide a fuel nozzle for pressurized fuel systems wherein a rotatable connection sleeve is mounted on the nozzle body rotatable between nozzle connecting and disconnecting positions, and the nozzle includes an interlock sensing the placing of the nozzle on the tank inlet and rotation of the connection sleeve to the locked condition cannot occur until the nozzle is properly aligned, oriented and located upon the tank inlet.
An additional object of the invention is to provide a fuel nozzle for a pressurized fuel system having an extendable and retractable valve positionable between open and closed conditions wherein an interlock prevents the nozzle from being disconnected from the tank inlet until the nozzle valve has been closed.
In the practice of the invention the fuel nozzle is adapted to be attached to a standard aircraft tank inlet. Such an inlet includes a self-sealing valve and lugs which cooperate with a bayonet-type connection on the nozzle permitting the fueling nozzle to be attached to the inlet. The nozzle includes an annular body having a flow passage defined therein and a connection end for mounting upon the tank inlet.
A connection sleeve concentrically rotatably mounted upon the nozzle body includes a bayonet connection for cooperating with the inlet lugs and placing of the nozzle end upon the tank inlet and rotation of the connection sleeve will lock the nozzle body to the tank inlet. A sensing ring concentrically mounted upon the nozzle engages the tank inlet and is axially displaced relative to the nozzle body upon the nozzle being aligned with the tank inlet and axially inserted thereon. Displacing of the sensing ring permits rotation of the connection sleeve on the body and insures that the nozzle is fully connected to the tank inlet prior to the nozzle valve being opened.
The nozzle passage includes an axially displaceable annular valve which closes the nozzle body passage to fluid flow in a retracted position, and permits fluid flow through the nozzle when the valve is extended. A rotatable valve actuator on the body includes a cam cooperating with a cam follower affixed to the valve wherein rotation of the cam actuator, which is in the form of an annular cam sleeve, axially displaces the valve relative to the body. Extension of the nozzle valve automatically displaces the tank inlet valve to an open condition permitting fluid flow through the nozzle into the tank. An interlocking slot defined in the connection sleeve also receives the cam follower and the configuration of the interlock slot on the connection sleeve prevents operation of the valve cam sleeve until the connection sleeve has been rotated on the body to the nozzle fully connected position.
Accordingly, the interlocks defined on the nozzle body prevent the nozzle valve from being opened until the nozzle is fully connected to the tank inlet, and the nozzle cannot be removed from the tank inlet until the nozzle valve has been closed.
The nozzle valve is of a hollow annular configuration free of internal actuating structure or components, and the connection sleeve and the valve cam sleeve are concentrically related to the valve body axis permitting the valve to be of a concise configuration, easily operable and handled, and economically manufacturable.